Pressurized air cooler



J. F. REESER 3,001,383

PRESSURIZED AIR COOLER Sept. 26, 1961 Filed May 25, 1959 2 Sheets-Sheet 1 l 6 I 3o 32 3 IO i L e 2 I I 38 o r 5/4 m H; 70 p 74 A Z I 48 25 p Q I 6 182 1,20 L

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JOHN F.' REESER Sept. 26, 1961 J. F. REESER 3,001,383

PRESSURIZED AIR COOLER Filed May 25, 1959 2 Sheets-Sheet 2 70 76 6886 25 Q \40 AIR SUPPLY y r j 84 I g 3 g INVENTOR. JOHN F. REESER Patented Sept. 26, 196! inc 3,091,383 PRESSURIZED AER COGLER John F. Reeser, San Diego, Calif., assignor to Ryan Aeronautical Co., San Diego, Calif. Filed May 25, 1959, Ser. No. 815,457 7 Claims. (Cl. 62-384) The present invention relates generally to air cooling equipment and more particularly to a pressurized air cooler.

The primary object of this invention is to provide an air cooler which produces a continuous flow of sub-zero air at high pressure, using air from a conventional pressurized supply such as that available in many industrial plants.

Another object of this invention is to provide an air cooler in which the pressure of the cooled air can be accurately controlled, the temperature being, in part, dependent on the outlet pressure.

Still another object of this invention is to provide an air cooler having no moving parts in the cooling system, the cooling being obtained by passing the air through Dry Ice.

A further object of this invention is to provide an air cooler having a double chamber structure for optimum cooling and temperature control and to prolong the effective life of the coolant.

Finally, it is an object to provide an air cooler of the aforementioned character which is simple, safe and convenient to operate and which will give generally eflicient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, as will be hereinafter fully described in the specification, particularly pointed out in the claims, and illustrated in the drawings which form a material part of this disclosure, and in which:

FIGURE 1 is a top plan view of the air cooler with the lid partially cut away;

FIGURE 2 is a sectional view taken on the line 2-2 of FIGURE 1; and

FIGURE 3 is a sectional view taken on the line 33 of FIGURE 2, the coolant being omitted for clarity.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawings.

The configuration of the cooler will be dictated by the particular installation. The illustrated embodiment comprises a casing 10, ordinarily but not necessarily upright and cylindrical, having an inner shell :12 and an outer shell :14 separated by a layer of insulationmateri-al 16, such as glass fiber, or the like. The lower end of the casing rests on a base 18 having an upper plate 20 and a lower plate 22, the base being enclosed by an outer rim 24 joining the edges of said plates, the space between the plates being filled by insulation 16. The upper end of the casing 10 is fitted with an end ring 26 joining the inner shell 12 to the outer shell 14, said outer shell having an upwardly extending annular flange 28 which forms a circular well for a lid 30. The lid Sil comprises an outer plate 32 and an inner plate 34 separated by a layer of insulation 16, said plates being joined by a peripheral rim 36. Fixed to the center of the outer plate 32 is a suitable handle 38 to facilitate removal of the lid.

Inside the casing 10 and concentric therewith is an inner container, illustrated as a heavy gauge cylinder 40 which is spaced above the base 18 and supported on a plurality of posts 42. The upper end of the cylinder 40 has an outwardly extending rim 44 to which is attached a heavy cover plate 46, said cover plate being seated on a plurality of studs 48 fixed in said rim and held in place by nuts 5!). A gasket 52 is fitted between the cover plate 46 and the rim 44 for proper sealing. Fixed to the upper surface of the cover plate 46 are two crossed lifting bars 54 having elongated hand slots 56 adjacent the ends thereof for handling the cover plate. The lower end of the cylinder 40 is closed but is fitted with a drain pipe 58 extending downwardly through the base 18 and having an extension pipe '60 leading to one side of said base, said extension pipe being fitted with a suitable valve 62 capable of containing the internal pressure in the cylinder.

Adjacent the top of the cylinder 40 is a large air inlet pipe 64 extending from the cylinder out through the casing Iii, said inlet pipe having an inlet fitting 66 thereon for connection to a conventional air pressure hose. Diametrically opposite the inlet pipe is a large outlet pipe 68 extending outwardly through the casing 10 and having a smaller outlet assembly including a pipe 70, a safety valve 72 and a pressure control valve 74, said control valve having an outlet nozzle 76 through which the cold pressurized air is delivered. Inside the cylinder 40 there is provided a heat exchanger-collector illustrated as a large diameter collector pipe 78 which reaches almost to the lower end of the cylinder and is connected at the top with the outlet pipe 68.

For ease of mobility the base 18 is mounted on a pluraiity of casters 8% and 82, or any suitable carriage may be used according to the size of the unit.

Cooling is accomplished by the use of solid carbon dioxide or Dry Ice, which vaporizes at a temperature of approximately -1l0 degrees F. The cylinder 40 is filled with lumps of Dry Ice, indicated at 84, to the level of the inlet pipe 64. The chamber defined between the casing it} and the inner container orcylinder 40* in the illus. trated embodiment is an annular space 86 and is filled with isopropyl alcohol, or an equivalent, indicated at 88, which will not become solidified at the temperature of Dry Ice. This alcohol 88 forms a cold retaining jacket around the cylinder 40 and has a maximum area of contact on the cylinder surfiace. For added cooling, further Dry Ice 84 may be broken up and immersed in the alcohol 33 and it has been found that this greatly prolongs the useful cooling operational periods of the unit.

The unit is connected to a source of pressurized air at the inlet fitting 66. Commercial air pressure systems delivering air at a pressure of about psi. are ideally suitable, although the unit may be used with any source of pressure from 60 to p.s.i. according to the size and strength of the structure. The air enters the inlet pipe 64 and must pass downwardly through the Dry Ice in the cylinder 40 to reach the collection pipe 78 and escape through the outlet pipe 68. In doing so, the air is greatly cooled Without the addition of any moisture. A certain amount of evaporated carbon dioxide becomes mixed with the air, but .the percentage surprisingly small. The pressure control valve 74 controls the size of the outlet orifice and consequently governs the outlet pressure, since a restricted outlet will cause the baclr pressure to build up in the cylinder 40. The greater the back pressure, the longer the air remains in the cylinder and thus the colder the air becomes. The large diameter of the collection pipe 78 provides a maximum of contact cooling area of Dry Ice on the pipe, so that the air in the pipe is cooled further.

The cylinder 40 is charged with Dry Ice by removing the cover plate 46, which is then secured tightly in place and sealed by the gasket 52 to retain internal pressure. The lid 30 merely rests on the end ring 26 under its own Weight, since no pressure is maintained in the annular space 86. After use, moisture or condensate in the cylinder 40 may be drained off through the valve 62,

While the cooler may be constructed in various sizes, one particularly useful size has a capacity of approximately 50 pounds of Dry Ice in the cylinder 40 and a further 50 pounds in the annular space 86, Dry Ice being readily available in these specific amounts. It has been found that a unit of this capacity will deliver cold air at substantially the air inlet pressure, at a temperature of 60 degrees F. for a continuous period of 6 to 8 hours.

The cost of operation of the cooler is extremely low, the Dry Ice being the only expendable item. By using a readily available pressured air supply, no pumping or recirculatory systems are needed in the cooler, which is self-contained and completely portable.

The cooler may be used for many purposes such as die quenching, cooling of machining, drilling or similar operations and in particular the cooling of precision machin ing operations where liquid coolant is undesirable for reasons of visibility and cleanliness. While the cooler is described as an air cooler, it will be obvious that any other gas supplied under pressure may be cooled with equal efficiency.

The operation of this invention will be clearly comprehended from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the drawings and the above recited objects. It will be obvious that all said objects are amply achieved by this invention.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawings are to be considered as merely illustrative rather than limiting.

I claim:

1. An air cooler, comprising: a casing; an inner container mounted in said casing in spaced relation thereto and defining a chamber between the inner container and the casing; said inner container having a closed end and an open end; a removable cover secured in sealed relation to said open end; an inlet communicating with the interior of said inner container and connected to a source of pressurized air; an outlet communicating with the interior of said inner container; a valve connected to said outlet to control the flow of air therethrough; and a quantity of generally solid coolant in said inner container between said inlet and said outlet.

2. An air cooler, comprising: a casing; a removable lid enclosing the upper end of said casing; an inner container mounted within said casing and defining a chamber therebetween; said inner container having a closed end and an open end; a removable cover plate secured in sealed relation to said open end; an inlet pipe communicating with the interior of said inner container and connected to a source of pressurized air; an outlet pipe communicating with the interior of said inner container; a valve connected to said outlet pipe to control the flow of air therethrough; a quantity of generally solid coolant in said inner container between said inlet pipe and said outlet pipe; and said chamber between said inner container and said casing containing a fluid coolant having a freezing point below the temperature of said solid coolant.

3. An air cooler, comprising: a casing; a removable lid enclosing the upper end of said casing; an inner container mounted within said casing and defining a chamber therebetween; said inner container having a closed end and an open end; a removable cover plate secured in sealed relation to said open end; an inlet pipe communicating with said inner container adjacent the open end thereof and extending outwardly through said casing and connected to a source of pressurized air; a heat exchanger-collector in said inner container; an outlet pipe communicating with said heat exchanger-collector and extending outwardly through said casing; a valve connected to said outlet pipe to control the flow of air there from; a quantity of generally solid coolant substantially filling said inner container and surrounding said heat exchanger-collector; and the chamber defined between said inner container and casing containing a fluid coolant having a freezing point below the temperature of said solid coolant.

4. An air cooler, comprising: a casing; an inner container mounted in said casing in spaced relation thereto and defining a chamber between the inner container and the casing; a quantity of generally solid coolant positioned in said inner container; an inlet communicating with the interior of said inner container whereby air to be cooled may be introduced into the interior of said inner container; an outlet communicating with the interior of said inner container, whereby cooled air may be obtained from the interior of said inner container; and a fluid coolant, having a freezing point below the temperature of said solid coolant, positioned in said chamber.

5. The combination of claim 4 including a quantity of a. generally solid coolant positioned in said chamber along with said liquid coolant.

6. An air cooler, comprising: a casing; an inner container mounted in said casing in spaced relation thereto and defining a chamber between and the inner container and the casing; and a quantity of generally solid coolant positioned in said inner container; a heat interchanger having an intake and an output positioned in said inner container; an inlet communicating with said intake of said heat interohanger, whereby air to be cooled may be introduced into said heat interchanger; and an outlet communicating with said output of said heat interchanger, whereby cooled air may be obtained from said heat interchanger; and a fluid coolant, having a freezing point below the temperature of said solid coolant, positioned in said chamber.

7. The combination of claim 6 including a quantity of a generally solid coolant positioned in said chamber along with said liquid coolant.

References Cited in the file of this patent UNITED STATES PATENTS 2,011,881 Stewart Aug. 20, 1935 2,060,482 Ballman Nov. 10, 1936 2,196,310 Kalin Apr. 9, 1940 2,377,590 Talalay June 5, '1945 2,507,866 Plesset et al. May 16, 1950 2,565,722 Dawley et a1. Aug. 28, 1951 

